Second-dialect acquisition in southwestern Pennsylvania

This thesis presents an analysis of second-dialect acquisition of Pittsburgh English phonological features. Pittsburgh English is the dialect spoken in southwestern Pennsylvania. There are two phonological features unique to the dialect: (i) the [ɔ] realization of the low-back vowel merger and (ii) monophthongal /aw/ (Johnstone et al. 2002). The current study is based on speech data collected from nine participants, native speakers of other dialects of English who now live in southwestern Pennsylvania. This analysis shows that these two phonological features can be acquired. This is the first study to examine Pittsburgh English as a second-dialect. Participants read a word list and a short reading passage adapted from data collection methods developed by Johnstone & Kiesling (2011). I analyzed words containing the low-back vowels and /aw/ using the Praat suite (Boersma & Weenink 2013), an acoustic program that extracts vowel frequencies. These frequencies reveal if speakers produce these vowels as found in their first-dialect or as they are produced in Pittsburgh English, their second-dialect. This analysis revealed that three participants have acquired the merger; of these three, two have also acquired monophthongal /aw/. Furthermore, one participant who lacks the merger has acquired the monophthong. This study also provides an analysis of two speaker variables – dialect awareness and gender – in the acquisition of phonological features. Participants’ awareness of the dialect, its features, and any opinions they have about the dialect area were determined through interviews conducted after they provided speech data. I propose that speakers who are aware of the use of monophthongal /aw/ in southwestern Pennsylvania do not produce the feature. I also propose that the presence of the feature correlates with gender, as it is only present in the speech of male participants. However, dialect awareness and gender do not account for the distribution of the merger. These second-dialect findings support previous first-dialect studies of Pittsburgh English (Johnstone & Kiesling 2008; Eberhardt 2009). The analysis put forth in this thesis has implications for dialect studies, as it shows that adults can acquire features of a second-dialect. Furthermore, the same speaker variables that factor into the distribution of first-dialect features are also applicable to second-dialect features. This analysis not only adds to the documentation of Pittsburgh English, but also more generally contributes to the understudied field of second-dialect acquisition

Innervation Patterns of Mystacial Vibrissae Support Active Touch Behaviors in California Sea Lions (Zalophus californianus)

Vibrissae, or whiskers, are highly developed sensory structures found in mammals. The follicles are referred to as Follicle Sinus Complexes (F-SC) due to the blood-filled sinuses. F-SCs are highly innervated compared to pelage. The most wellknown group of vibrissae, mystacial vibrissae, are found around the muzzle in mammals. Pinnipeds have the largest and most innervated vibrissae of any mammal. More aquatic mammals tend to have larger F-SCs and greater innervation investment (axons per FSC). Behavioral performance studies have shown that California sea lions Zalophus californianus (CSL, an otariid) excel at haptics whereas harbor seals Phoca vitulina (a phocid) excel at hydrodynamic trail following. The data presented in this thesis will infer vibrissal function from these studies. To date there has been no thorough investigation of innervation investment in an otariid. The objectives of this study were to investigate the innervation of the largest F-SCs, compare the innervation and microstructure to the most medial F-SCs, and compare the dorsal to ventral F-SCs. Follicles were dissected from tissues obtained from stranding programs and processed for histology. Axons were counted from wet mounted cross-sections. Asymmetry of axon bundles was present in all F-SC cross sections and have not been described before as well as blood vessels seen entering the DC of the LCS. There was a mean of 75±5 F-SCs per face muzzle. Innervation increased from medial (705 ±125 axons/F-SC) to lateral (1447±154) as well as from dorsal (541 ± 60) to the ventral F-SCs (1493 ± 327). Lateral F-SCs axon counts were similar to those in other pinniped studies. The total innervation from lateral axon counts (108,525 axons) agree with other studies but total innervation from all six areas (86,042 axons) was 20% less than values from only lateral F-SCs. Axon density of medial F-SCs were significantly more than lateral F-SCs. This finding is congruent with CSL behavioral performance data that suggest they excel at haptic touch. We found no substantial evidence to differentiate which F-SCs fall into micro- or microvibrissae categories. To date no study has investigated the dorsal-ventral micro anatomical and innervation patterns in any pinniped

Second-dialect Acquisition in Southwestern Pennsylvania

This thesis presents an analysis of second-dialect acquisition of Pittsburgh English phonological features. Pittsburgh English is the dialect spoken in southwestern Pennsylvania. There are two phonological features unique to the dialect: (i) the [ɔ] realization of the low-back vowel merger and (ii) monophthongal /aw/ (Johnstone et al. 2002). The current study is based on speech data collected from nine participants, native speakers of other dialects of English who now live in southwestern Pennsylvania. This analysis shows that these two phonological features can be acquired. This is the first study to examine Pittsburgh English as a second-dialect. Participants read a word list and a short reading passage adapted from data collection methods developed by Johnstone & Kiesling (2011). I analyzed words containing the low-back vowels and /aw/ using the Praat suite (Boersma & Weenink 2013), an acoustic program that extracts vowel frequencies. These frequencies reveal if speakers produce these vowels as found in their first-dialect or as they are produced in Pittsburgh English, their second-dialect. This analysis revealed that three participants have acquired the merger; of these three, two have also acquired monophthongal /aw/. Furthermore, one participant who lacks the merger has acquired the monophthong. This study also provides an analysis of two speaker variables – dialect awareness and gender – in the acquisition of phonological features. Participants’ awareness of the dialect, its features, and any opinions they have about the dialect area were determined through interviews conducted after they provided speech data. I propose that speakers who are aware of the use of monophthongal /aw/ in southwestern Pennsylvania do not produce the feature. I also propose that the presence of the feature correlates with gender, as it is only present in the speech of male participants. However, dialect awareness and gender do not account for the distribution of the merger. These second-dialect findings support previous first-dialect studies of Pittsburgh English (Johnstone & Kiesling 2008; Eberhardt 2009). The analysis put forth in this thesis has implications for dialect studies, as it shows that adults can acquire features of a second-dialect. Furthermore, the same speaker variables that factor into the distribution of first-dialect features are also applicable to second-dialect features. This analysis not only adds to the documentation of Pittsburgh English, but also more generally contributes to the understudied field of second-dialect acquisition

Thoughts on ministerial adaptation

Thesis (M.A.)--Boston Universit

Evaluation of Ventilation Assistance for Improving Respiratory Reproducibility in Radiation Therapy

Background: Respiratory motion affects all tumor sites in the thorax and abdomen. Variations of the respiratory pattern cause variations of the tumor motion which can result in differences between the planned and delivered dose distributions. Previous breathing guidance techniques have been investigated to improve respiratory reproducibility; however, ventilation assistance has not been investigated. We evaluated using bi-level positive airway pressure (BIPAP) ventilation assistance for improving respiratory reproducibility in patients with tumor sites impacted by respiratory motion. Methods: Written informed consent was obtained for 10 patients currently undergoing radiation therapy treatment. Patients participated in sessions over their course of treatment, which occurred either before or after their radiation treatments. We collected and analyzed unassisted free- breathing (FB) and BIPAP ventilation-assisted respiratory volume data using spirometry. Patients used two BIPAP ventilators which both aimed to deliver the same volume of air each breath (i.e. tidal volume); however, one permitted patient triggering (i.e. permitted patients to initiate each breath) and the other did not. Intra-session and inter-session variation metrics were calculated for each patient using the platform-specific (i.e. FB or BIPAP) tidal volumes. We compared variation metrics between the platforms using the Wilcoxon signed-rank test, with a level of significance of 0.05. Results: The BIPAP ventilator which permitted patient triggering was well tolerated; however, the other was not as well tolerated. Both BIPAP ventilators significantly reduced the intra-session tidal volume variation (p = 0.022 and p = 0.007) compared to FB. Neither of the BIPAP ventilators significantly reduced the inter-session tidal volume variation compared to FB (p = 0.203 and p = 0.074). Conclusions: Based on the high correlation of tidal volume to tumor motion, any reduction of the tidal volume variation could result in a reduction of the tumor motion variation. Future work will include an investigation into the possible clinical benefits of using BIPAP ventilation assistance to reduce tumor motion variations

Investigation of smooth specimen scc test procedures; variations in environment, specimen size, stressing frame, and stress state

The variables studied in the stress-corrosion cracking performance of high strength aluminum alloys were: (1) corrosiveness of the environment, (2) specimen size and stiffness of the stressing system, (3) interpretation of transgranular cracking, and (4) interaction of the state of stress and specimen orientation in a product with an anisotropic grain structure. It was shown that the probability of failure and time to fracture for a specimen loaded in direct tension are influenced by corrosion pattern, the stressing assembly stiffness, and the notch tensile strength of the alloy. Results demonstrate that the combination of a normal tension stress and a shear stress acting on the plane of maximum susceptibility in a product with a highly directional grain cause the greatest tendency for stress-corrosion cracking

A study of environmental characterization of conventional and advanced aluminum alloys for selection and design. Phase 1: Literature review

A review of the literature is presented with the objectives of identifying relationships between various accelerated stress corrosion testing techniques, and for determining the combination of test methods best suited to selection and design of high strength aluminum alloys. The following areas are reviewed: status of stress-corrosion test standards, the influence of mechanical and environmental factors on stress corrosion testing, correlation of accelerated test data with in-service experience, and procedures used to avoid stress corrosion problems in service. Promising areas for further work are identified

Evaluation of Stress Corrosion Cracking Susceptibility Using Fracture Mechanics Techniques, Part 1

Stress corrosion cracking (SSC) tests were performed on 13 aluminum alloys, 13 precipitation hardening stainless steels, and two titanium 6Al-4V alloy forgings to compare fracture mechanics techniques with the conventional smooth specimen procedures. Commercially fabricated plate and rolled or forged bars 2 to 2.5-in. thick were tested. Exposures were conducted outdoors in a seacoast atmosphere and in an inland industrial atmosphere to relate the accelerated tests with service type environments. With the fracture mechanics technique tests were made chiefly on bolt loaded fatigue precracked compact tension specimens of the type used for plane-strain fracture toughness tests. Additional tests of the aluminum alloy were performed on ring loaded compact tension specimens and on bolt loaded double cantilever beams. For the smooth specimen procedure 0.125-in. dia. tensile specimens were loaded axially in constant deformation type frames. For both aluminum and steel alloys comparative SCC growth rates obtained from tests of precracked specimens provide an additional useful characterization of the SCC behavior of an alloy

A study of environmental characterization of conventional and advanced aluminum alloys for selection and design. Phase 2: The breaking load test method

A technique is demonstrated for accelerated stress corrosion testing of high strength aluminum alloys. The method offers better precision and shorter exposure times than traditional pass fail procedures. The approach uses data from tension tests performed on replicate groups of smooth specimens after various lengths of exposure to static stress. The breaking strength measures degradation in the test specimen load carrying ability due to the environmental attack. Analysis of breaking load data by extreme value statistics enables the calculation of survival probabilities and a statistically defined threshold stress applicable to the specific test conditions. A fracture mechanics model is given which quantifies depth of attack in the stress corroded specimen by an effective flaw size calculated from the breaking stress and the material strength and fracture toughness properties. Comparisons are made with experimental results from three tempers of 7075 alloy plate tested by the breaking load method and by traditional tests of statistically loaded smooth tension bars and conventional precracked specimens